Shade Tree vs. Your Lawn: Which Will Win?
May 11, 2015
Across Dallas-Fort Worth there are large, beautiful oaks, sprawling pecans and many other large trees trees that offer up much-needed shade. If you own a home, planting a shade tree in your landscape offers benefits such as lower air conditioner bills, plus shaded outdoor areas for lounging and entertaining. Shade trees are pretty non-negotiable in our hot Texas climate. Unfortunately, all that shade can cause some serious challenges for your beloved lawn.
Were you told that St. Augustine is more shade tolerant, only to find that it is in decline under your large shade tree? There’s a big difference between “shade tolerant” and “shade loving” plants. While some plants may “tolerate” a bit more shade, that doesn’t mean they’ll perform at their best in shady conditions. The reality is that all lawn grasses are sun plants; they need a good six hours of sun to thrive. Even St. Augustine. While St. Augustine does tolerate a bit more shade than say Bermuda grass, it doesn’t grow well in full or dense shade. As trees mature and cast more shade, you’ll typically find even your St. Augustine lawns thinning out. Too much shade also weakens your lawn and makes it more susceptible to pests, diseases, drought and cold damage.
Not only is shade a problem for local lawns, trees will typically outcompete lawns for water and nutrients.
Why does your neighbor grow grass under THEIR shade tree?
You might wonder why your neighbor across the street has lush green grass under their large oak tree and you don’t. While it might seem like they have the same light levels, or “shade” as you, their lawn most likely receives more direct sunlight. Often the orientation of the sun is different on their property or the height of the tree canopy that allows in more light. Not all shade is equal. You might be surprised to learn that the placement of your house, tree and height of the canopy may result in much more shade on your lawn than your neighbor’s.
Can you prune trees to let the light shine through?
Thinning out the canopy to allow more light to hit your lawn could eventually mean big problems for your shade tree. This technique is incredibly difficult and should only be performed or overseen by an experienced certified arborist. Many people in our area try this option with very damaging results. Improper pruning or too much thinning of large trees typically weakens them. Once a storm rolls in with high winds and heavy rain, your weakened tree may not be able to stand up to the elements. Your tree, or even your property, could suffer significant damage, or you could lose the entire tree.
Will more water and fertilizer help your lawn?
No amount of extra water or fertilizer can replace sunlight. Grass needs the sunlight to make the energy it needs to thrive. Trying to make up for a lack of sunlight with more water or fertilizer won’t solve your shade problem. But it will waste water and cause a host of fungal diseases in your lawn.
What are my options?
Unfortunately, trying to grow a lush lawn in heavy shade isn’t a realistic goal. As trees grow and cast more shade, you’ll need to transition to shade-appropriate ground covers such as liriope, mondo grass, Persian ivy, lamium, Asian jasmine, ajuga and moneywort. While large trees tolerate established ground covers or shrubs under their canopy, it’s best not to do regular digging or planting in the tree’s root zone. Try to avoid having ground covers grow against the base of your tree trunk to avoid damage or decay. You also want to make sure you’re not over-watering plantings under your trees. Be careful of ivy growing up your trees. Ivy growing up the trunk could lead to trunk damage that will invite pests and disease to attack your tree.